opinions on plug condition

[theo]

I put today aside to play with my air screw/needle and see if I could tune the motor a bit better. Looking at the original plug, it was black and oily (no pic). I thought it was a bit too rich. Here are the details from today's experiment:

'17 300RR
plug on the left (dark one)
air screw 2.5
38 pilot
needle N2ZW 2nd clip
165 main

plug on the right
air 2.5
38 pilot
N2ZW 1st clip
165 main

I ride at 4000-5000' in the Canadian Rockies. I also dropped my float slightly because I was leaking a bit of gas and had terrible mileage. Today the mileage improved and leaking stopped. Also the engine performed better with the right plug installed.

2 questions: Am I on the right track here or am I missing the boat? If I'm off track, what can I do to correct?

Thanks!

[McKay]

Still too rich, try a 162 main and move needle clip around as required to get closer to brown color.

[McKay]

You could also leave all alone and try a 35 AS jet.

[farmerpaul]

Theo,

You need to get your pilot jet adjusted to your altitude first, before you play with the main. Read any 2 stroke tuning article and it will tell you this (not just me saying it).

Warm your engine up to normal operation temperature. Increase the tickover by approx. 500 rpm (this just helps prevents the engine from stalling). Wind in the airscrew and then out until you find the point where the tickover is the highest. If the highest tickover is less than a turn out (from fully in) your pilot is too lean. If the highest tickover is more than 2.5 turns out (again from fully in) your pilot is too rich. Adjust the pliot jet accordingly.

Remember, the pilot jet affects the whole rev range. Once you have the right pilot jet, you can play with mains and needles.

Regards

Paul

[theo]

Sorry for the late reply. Thanks for the feedback! My plan is to try the 35 pilot jet and leave the needle on the 1st clip. Given what you guys described and what I found when I adjusted the air screw (no real rise in idle 'til 3 turns out), I think that will help. My main is already a bit leaner than what the chart says, so I think I'm good on that.

On a related note, based on the photo, should I be worried about running too hot? How much room do I have to go leaner before I need to worry about over heating?

[McKay]

Your looking for a milk chocolate brown on the spark plug insulator, disregard every other part of the plug for color. When you get to that color then you are balancing between too lean and just right. I stay a bit darker on insulator than milk chocolate to be safe and keep her cool.

[dirtbird]

I answered in your TT post as well.

For your elevation you should try N2ZJ or even N2ZK instead of going to 1st clip position on the std needle.
I use those on almost sea level (0-500 meters) and with temps 25C and above.
Remember while approaching to stop to kill your engine with some load, otherwise you will get the oily look on your plug.